The present invention relates to an electronic component module and in particular to an electronic component module on which electronic components operating in a plurality of frequency bands are mounted.
Recently, there is a growing need for a more compact and higher-performance communications system used in the microwave band or millimeter band with easy broadband applicability and higher resolution. As a solution to satisfy such a need and reduce transmission loss between the electronic components of a communications system, there is known a technology which packs high-frequency devices or electronic components such as an amplifier, a mixer, an oscillator and a multiplier into an electronic component module in the form of a package, as mentioned in the Japanese Patent Laid-Open No. 237867/1997.
The Japanese Patent Laid-Open No. 326488/1984 discloses a technology to shield an input/output terminal while keeping out of the way of cable routing in order to avoid the influence of malfunctions caused by an electromagnetic wave in such an electronic component module.
However, the technologies described in these official gazettes require dedicated substrates and cases. Fabricating an electronic component module by using such a substrate and a case requires a complicated manufacturing process and time, thus resulting in higher costs.
Another approach of advancing the feature of the electronic component module which installs electronic components operating in frequency bands different from each other in a single package presents a problem of interference between electronic components operating in frequency bands different from each other according to the aforementioned technology.
In order to suppress propagation loss or improve antenna efficiency, it is preferable to use a member with a low dielectric constant for a mounting substrate on which electronic components are mounted. The problem is that a member with a low dielectric constant is generally made of resin and has low heat resistance. For example, when an electronic component is mounted by way of heat-compression bonding of an Au or Au—Sn alloy which requires heat treatment at some 400 degrees centigrade, the electronic component cannot be mounted on a resin substrate with low heat resistance, so that only limited electronic components can be mounted on such a resin substrate.